Different keymaps per hardware keyboard is an idea I have liked and
advertised since a long time. My vision was to create a single preference
application for "Input" devices, which would present the attached devices,
and display the configuration GUI (which would be mostly the refactored code
from the existing preflets) depending on which device is selected. I never
got far in implementing this idea and pretty much the only change I did was
to give each input_server keyboard device instance it's own copy of the
keymap. The only fundamental difference I see in your proposal is that key
codes can be greater than 127, but I believe they are stored in the key
event BMessage as int32 ("key"), so it wouldn't be a problem. I don't
envision the need for a separate driver. Rather the existing input_device
add-ons should look up their settings (keymap, state of modifier keys) based
on the device name exported by the driver (mechanism needs to be added,
perhaps).
